Individual organisms do not evolve. Populations evolve.
Evolution is, roughly speaking, a change in the frequency of occurrence of genes in a population. You received your genes at the moment of conception, and they are now with you for life. You cannot evolve. All you can do is conceive a new life. You are the evolution of your parents. Your children are your evolution.
The depth of the navel depends on several reasons. The most important is the thickness of the subcutaneous fat. The "bottom" of the umbilical cavity is fixed to the aponeurosis, gaining subcutaneous fat, we immerse it. Olena, I have to upset you. This is not evolution.